1. Field of the Invention
The present invention relates to a flat type plasma discharge display device and its driving method.
2. Description of the Related Art
Hitherto, an alternating-current type display device utilizing a plasma discharge, or a so-called AC (alternating-current) type plasma display panel (PDP) has been known.
This AC type PDP is available in two-electrode constitution and three-electrode constitution.
An ordinary PDP in three-electrode constitution is shown in a perspective exploded view in FIG. 27, that is, as shown in this schematic structural diagram in an open state, first and second substrates 51 and 52 each made of, for example, a glass substrate are placed face to face with a specified interval through a partition wall 53 interposed between the two, and their peripheral parts are sealed with glass frit or the like, and a flat type display container is composed.
For example, on the inner surface of the first substrate 51, there are formed a scanning electrode (first discharge sustaining electrode) 54 serving also as one of the discharge sustaining electrodes and other discharge sustaining electrode (second discharge sustaining electrode) 55 (in FIG. 27, only a pair of first and second discharge sustaining electrodes corresponding to one scanning line are shown), and on the inner surface of the second substrate 52, there is formed an address electrode 56 in a direction intersecting with the scanning electrode 54 and the discharge sustaining electrode 55.
On the electrode forming surfaces of the both substrates 51 and 52, dielectric layers 57 are laminated by printing or other means, and a surface protective layer 58 made of MgO or the like is formed further on the surface thereof.
On the second substrate 52, for example, a fluorescent material 59 for emitting a visible light by ultraviolet rays generated by discharge is coated.
The flat display container formed by the first and second substrates 51 and 52 is filled air-tightly with a gas suited to the discharge.
A driving circuit is connected to each electrode, and a discharge is generated in the space enclosed by the substrates 51 and 52 and the partition wall 53, and by the ultraviolet rays generated by this discharge, the fluorescent material 59 is excited to emit a light, and a target or intended display is made.
The voltage waveform for driving such a PDP is schematically shown in FIG. 9. This driving is divided into a xe2x80x9cscanning discharge periodxe2x80x9d for determining a pixel for causing an ordinary discharge, and a xe2x80x9csustained discharge periodxe2x80x9d for sustaining the discharge of the thus determined pixel.
First, in the scanning discharge period, when scanning the pixel desired to be discharged, a voltage equal to or higher than a discharge start voltage is applied between the scanning electrode 54 and the address electrode 56 at a position corresponding to the pixel. As a result, the pixel at this position is set in discharge start state, and hence the discharge pixel is selected. This selection is made for each one of a plurality of address electrodes for one scanning electrode. That is, the same number of pixels as the number of address electrodes can be driven independently.
Therefore, by scanning a plurality of scanning electrodes sequentially by each scanning line and changing over the voltage of the address electrode 56 every time according to the image desired to be displayed, all pixels for composing one screen can be controlled.
Next, in the sustained discharge period, between the scanning electrode 54 and the discharge sustaining electrode 55, an AC voltage waveform called a discharge sustaining voltage is applied. At this time, as to the pixel once applied with the voltage equal to or higher than the discharge start voltage in the scanning discharge period, its discharge is sustained thereafter only by application of discharge sustaining voltage, and the luminous display continues. This is a so-called memory effect.
FIG. 9 shows the driving waveform for displaying about one address electrode 56.
FIG. 9A shows the display signal waveform applied to this one address electrode 56, and in this case, for example, the pixels positioned at the intersections with the first, second and fourth horizontal scanning lines are discharged or turned on, and in this case, a specified ON voltage Va is supplied in sections xcfx841, xcfx842, xcfx844.
On the other hand, in each scanning electrode 54 corresponding to each horizontal scanning line, as shown in FIG. 9B1, B2, B3 . . . , to the scanning electrodes 54 adjacent in the vertical direction, a specified ON voltage Vb of reverse polarity to the voltage Va is changed over and applied sequentially in sections xcfx841, xcfx842, xcfx843, xcfx844 . . . At this time, to the discharge sustaining electrode 55 making a pair with each scanning electrode 54, no voltage is applied as shown in FIG. 9C.
In the next sustained discharge period, in each horizontal scanning line, pulse voltages shown in FIGS. 9B1, B2, B3 . . . and C are applied to the scanning electrodes 54 and the confronting discharge sustaining electrodes 55.
When such driving waveforms are applied to the respective electrodes, as shown in FIG. 9D1, D2, D3 . . . , in the scanning discharge period, a voltage of Va+Vb is selectively applied in section xcfx841 between the scanning electrode 54 and one address electrode 56 in the first horizontal scanning line, in section xcfx842 between the scanning electrode 54 and one address electrode 56 in the second horizontal scanning line, and, although not shown, in section xcfx844 between the scanning electrode 54 and one address electrode 56 in the fourth horizontal scanning line.
At this time, by preliminarily selecting the Va+Vb equal to or higher than the aforesaid discharge start voltage, and selecting the individual voltages Va and Vb at a voltage not reaching the discharge start voltage, the discharge start state, that is, the ON state is established only for the pixels at the intersection with the address electrode 54 in the selected first, second and fourth horizontal scanning lines.
The pixels once turned on are kept in discharge state in the subsequent sustained discharge period as the desired AC voltage shown in FIG. 9E is applied sequentially between each scanning electrode and the discharge sustaining electrode.
Thus, discharge, that is, luminescence about the entire screen, that is, all pixels can be controlled by display signals, and the target or intended image can be displayed.
In the display devices recently advanced remarkably, such as a personal computer, an office work station, a wall-hang television receiver, a large-screen television receiver or the like, there is an increasing demand for higher definition, higher luminance and lower power consumption. In the trend of larger screen, at the same time, there are problems in power consumption and response due to increase in the electrode resistance.
In order to solve such problems, the present applicant formerly proposed a flat type plasma discharge display device, for example, in Japanese Patent Application No. 10-32974 and Japanese Patent Application No. 10-37546.
In these proposed display devices, it is possible to narrow the interval between a pair of discharge sustaining electrodes for discharge sustaining or the interval between the discharge sustaining electrode and a discharge start address electrode, so that the discharge mode may be substantially realized by a cathode glow discharge. Thus, by narrowing the interval between the electrodes, a higher definition is realized, and it is further possible to improve characteristics of cathode glow discharge, such as higher luminance and lower power consumption.
In the display device disclosed in Japanese Patent Application No. 10-32974 and Japanese Patent Application No. 10-37546 mentioned above, by arranging and forming the discharge sustaining electrode group and the address electrode group on a common substrate side, mutual positioning therebetween and manufacture thereof are facilitated.
That is, in this flat type plasma a discharge display device, for example, as an open schematic perspective view thereof is shown in FIG. 28, first and second substrates 1 and 2 are placed face to face across a specified interval, and the peripheral parts thereof are fritted and sealed to compose an airtight sealed flat display container, and this container is packed with a discharge gas.
As its essential parts are shown in a schematic plan view in FIG. 29, on the common first substrate 1, a discharge sustaining electrode group X and an address electrode group Y are formed.
The discharge sustaining electrode group X is formed of plurality of pairs of first discharge sustaining electrodes XA (XA-1, XA-2, XA-3 . . . ) and second discharge sustaining electrodes XB (XB-1, XB-2, XB-3 . . . ) disposed which are respectively extended in one direction, and the address electrode group Y is flatly formed of a plurality of address electrodes Y1, Y2, Y3 . . . formed along the direction intersecting with the discharge sustaining electrodes XA (XA-1, XA-2, XA-3 . . . ) and XB (XB-1, XB-2, XB-3 . . . ). Insulating layers 14 are interposed at least in the intersections of these first and second discharge sustaining electrodes XA (XA-1, XA-2, XA-3 . . . ) and XB (XB-1, XB-2, XB-3 . . . ), and the address electrodes Y1, Y2, Y3 . . . of the address electrode group Y.
To each of the address electrodes Y1, Y2, Y3 . . . , discharge start address electrodes C disposed on the substrate 1 are electrically coupled such that with respect to each pair of first and second discharge sustaining electrodes XA and XB, they oppose to each first discharge sustaining electrode XA with a specified narrow interval.
FIG. 30 is a schematic electrode configuration showing the relation among the first and second discharge sustaining electrodes XA (XA-1, XA-2, XA-3 . . . ) and XB (XB-1, XB-2, XB-3 . . . ), the address electrodes Y (Y1, Y2, Y3 . . . ), and discharge start address electrodes C thereof.
The invention, relating to the flat type plasma discharge display device such as the display device as mentioned above, is intended to present a flat type plasma discharge display device and its driving method capable of enhancing the luminance or facilitating the driving circuit.
In the flat type plasma a discharge display device of the invention, a discharge sustaining electrode group arranging a plurality of discharge sustaining electrodes, and an address electrode group arranging a plurality of address electrodes are formed on a common substrate or on mutually different substrates.
A plurality of plasma discharge parts are formed for one discharge start part by the address electrodes, and the interval between each pair of discharge sustaining electrodes in discharge sustaining relating to each plasma discharge part is set equal to or less than 50 xcexcm, and the plasma discharge display is realized mainly by the cathode glow discharge.
In the driving method of flat type plasma a discharge display device of the invention, in the flat type plasma a discharge display device having such constitution, a target or intended display is made in a discharge start state between the address electrode of the discharge start part relating to the selected plasma discharge part and the discharge sustaining electrode.
Also in the driving method of flat type plasma a discharge display device of the invention, in the above-mentioned driving method, in making of such intended display, as the driving method for forming one screen by first and second fields, in the first field, a display is made by a part of plasma discharge parts corresponding to each discharge start part, and in the second field, a display is made by the other plasma discharge parts corresponding to each discharge start part.
Further, in the driving method of flat type plasma a discharge display device of the invention, in the driving method mentioned above, in making of such intended display, the intended display is made by driving and displaying a plurality of plasma discharge parts corresponding to the discharge start parts simultaneously.
In the flat type plasma a discharge display device of the invention, a discharge sustaining electrode group arranging a plurality of discharge sustaining electrodes, and an address electrode group arranging a plurality of address electrodes individually having a discharge start address electrode are formed on a common substrate, the discharge sustaining electrodes and the address electrodes are disposed so as to intersect through an insulating layer, and a plurality of plasma discharge parts are formed for each one of the discharge start address electrodes.
In the driving method of flat type plasma a discharge display device of the invention, the driving method is basically same as each of the driving method mentioned above.
Moreover, in the flat type plasma a discharge display device of the invention, a first substrate and a second substrate are placed to face each other while keeping a specified interval therebetween, a discharge sustaining electrode group formed by arranging a plurality of discharge sustaining electrodes is formed at the first substrate side, an address electrode group formed by arranging a plurality of address electrodes is formed at the second substrate side, a plurality of plasma discharge parts are formed in one discharge start part of the address electrodes, and the interval between the discharge sustaining electrodes forming a pair in discharge sustaining relating to the plasma discharge part is set equal to or less than 50 xcexcm, and plasma discharge display is made mainly by cathode glow discharge.
In the driving method of flat type plasma a discharge display device of the invention, too, the driving method is basically same as each of the driving method mentioned above.
Also, in the flat type plasma a discharge display device of the invention, a first substrate and a second substrate are place to face each other while keeping a specified interval therebetween, a discharge sustaining electrode group formed by arranging a plurality of discharge sustaining electrodes is formed at the first substrate side, an address electrode group formed of a plurality of partition walls extended in a direction intersecting with the main extending direction of the discharge sustaining electrodes while keeping a specified interval, and a plurality of address electrodes arranged and formed on each one of the partition walls along the extending direction of the partition walls is formed at the second substrate side, a plurality of plasma discharge parts are formed in one discharge start part of the address electrodes, and the interval between discharge sustaining electrodes forming a pair in discharge sustaining relating to the plasma discharge part is set equal to or less than 50 xcexcm, and plasma discharge display is realized mainly by cathode glow discharge.
In the driving method of flat type plasma a discharge display device of the invention, too, the driving method is basically same as each of the driving method mentioned above.
Thus, according to the invention, as described above, since a plurality of plasma discharge parts are formed for one discharge start part, that is, one address electrode or discharge start address electrode, the number of address electrodes or discharge start address electrodes may be decreased, and the area is reduced, so that the number of pixels, that is, the number of plasma discharge parts can be increased within the same area while keeping a sufficient width of the electrode pixel.
In its driving, as will be clear from the description given later, it is possible to drive the flat type plasma display device without using any particular signal processing circuit or the like.
By simultaneously turning on and off the plurality of plasma discharge parts, it is intended to display at high luminance.